1. Field of the Invention
The present invention relates to compositions capable of markedly inhibiting formation of metastatic lesion of cancer cells and also relates to novel sugar lactams having such an activity.
2. Description of the Prior Art
Main trends in known anticancer agents are drugs to kill malignant cells via cytotoxicity possessed by substances or via human immune system. However, these drugs are yet unsatisfactory for treatment of cancer. To solid cancer, treatment by surgical operation or radiotherapy has been applied and chances of success are greatly improved to the extent that these treatments could eliminate primary cancer. However, the most serious factor for affecting prognosis of the patient with cancer to whom these treatments have been applied is cancer metastasis. Accordingly, it is expected that the effectiveness of the existing various therapies could be further enhanced by inhibiting metastasis of cancer cells. However, there are few substances showing inhibition of metastasis as their main activity and none of them has been used in the clinical field.